Kotlin Release History
Every release with its date and what changed. Links go to our summary and the official notes.
Latest Kotlin version
Kotlin 2.4.21 Stable
Released
Kotlin v2.4.21 is a patch release focused on stability, fixing bugs across Wasm, JVM reflection, JavaScript, serialization, Gradle Native, and scripting.
Next up: Kotlin 2.5.0-Beta2 (preview, Oct 21, 2026)
Latest version, betas and how to upgrade →All Kotlin releases 100 versions
-
v2.5.0-Beta2 Pre-release View Details →
Kotlin v2.5.0-Beta2 advances Multi-Field Value Classes to alpha, stabilizes IntrinsicConstEvaluation, and enables the Return Value Checker by default.
-
v2.4.21 Latest View Details →
Kotlin v2.4.21 is a patch release focused on stability, fixing bugs across Wasm, JVM reflection, JavaScript, serialization, Gradle Native, and scripting.
-
v2.4.21-RC Pre-release View Details →
Kotlin 2.4.21-RC focuses on bug fixes across Wasm, JS, reflection, and scripting.
-
v2.5.0-Beta1 Pre-release View Details →
Kotlin 2.5.0-Beta1 introduces strict equals checks with improved smart casting, JVM bytecode version 27 support, and a reworked class initialization scheme for…
-
v2.4.20 View Details →
Kotlin v2.4.20 enables Native incremental compilation by default and introduces collection literals with companion block support, along with short-form…
-
v2.4.20-RC3 Pre-release View Details →
Kotlin v2.4.20-RC3 is a small patch release focused on compiler stability.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
v2.3.20 View Details →
Kotlin 2.3.20 delivers significant improvements to collection literals, Analysis API capabilities, and Wasm compilation efficiency.
-
v2.3.20-RC3 Pre-release View Details →
Kotlin v2.3.20-RC3 addresses critical tooling issues for Kotlin/Wasm and Kotlin/Native development.
-
v2.3.20-RC2 Pre-release View Details →
Kotlin v2.3.20-RC2 focuses on stability and performance fixes across the compiler, JVM reflection, and build tooling.
-
v2.3.20-RC Pre-release View Details →
Kotlin v2.3.20-RC focuses on stability and performance fixes across WebAssembly, Native, and Compose compilation.
-
v2.3.10 View Details →
Kotlin v2.3.10 focuses on compiler stability and reliability with fixes for overload resolution, null safety handling, and reflection errors.
-
v2.3.10-RC2 Pre-release View Details →
Kotlin v2.3.10-RC2 is a maintenance release focused on stability improvements.
-
v2.3.20-Beta2 Pre-release View Details →
Kotlin v2.3.20-Beta2 delivers significant improvements to collection literals, JavaScript ES6 support, and Java interoperability while stabilizing explicit…
-
v2.3.10-RC Pre-release View Details →
Kotlin 2.3.10-RC focuses on stability fixes across the compiler, Compose integration, and reflection APIs.
-
v2.3.20-Beta1 Pre-release View Details →
Kotlin v2.3.20-Beta1 introduces Collection Literals inference, unnamed local variables, and expanded contract support for property accessors.
-
v2.3.0 Major Release View Details →
Kotlin 2.3.0 delivers significant K2 compiler maturity with 50+ critical bug fixes for type inference, generics, and Java interop, while introducing…
-
v2.3.0-RC3 Pre-release View Details →
Kotlin v2.3.0-RC3 addresses critical compiler and standard library bugs discovered in the 2.3 release cycle.
-
v2.3.0-RC2 Pre-release View Details →
Kotlin v2.3.0-RC2 addresses critical compiler issues affecting generic type handling with functional interfaces and enhances plugin compatibility diagnostics.
-
v2.3.0-RC Pre-release View Details →
Kotlin v2.3.0-RC delivers critical bug fixes across debugging, multiplatform compilation, and platform-specific backends.
-
v2.3.0-Beta2 Pre-release View Details →
Kotlin 2.3.0-Beta2 delivers significant K2 compiler stability with 40+ critical bug fixes for type inference, generics, and Java interop.
-
v2.2.21 View Details →
Kotlin 2.2.21 is a maintenance release focused on stability across mobile and multiplatform development.
-
v2.2.21-RC2 Pre-release View Details →
Kotlin v2.2.21-RC2 addresses critical Gradle and Native tooling issues affecting Klibs cross-compilation workflows.
-
v2.3.0-Beta1 Pre-release View Details →
Kotlin v2.3.0-Beta1 introduces local type aliases, completes K2 decompiler implementation, and significantly enhances WASM support with annotation…
-
v2.2.21-RC Pre-release View Details →
Kotlin v2.2.21-RC addresses critical stability issues across WebAssembly, Native, and Gradle tooling.
-
v2.2.20 View Details →
Kotlin v2.2.20 delivers significant improvements to the K2 compiler's Analysis API with 70+ bug fixes addressing FIR resolution, light classes, and type…
-
v2.2.20-RC2 Pre-release View Details →
Kotlin v2.2.20-RC2 delivers critical bug fixes across Wasm, compiler, and native interop tooling.
-
v2.2.20-RC Pre-release View Details →
Kotlin v2.2.20-RC delivers critical stability fixes across compiler, Wasm, JavaScript, and Compose backends.
-
v2.2.10 View Details →
Kotlin v2.2.10 is a maintenance release focused on stability and bug fixes across all platforms.
-
v2.2.10-RC2 Pre-release View Details →
Kotlin v2.2.10-RC2 is a maintenance release addressing critical compiler bugs across Android, iOS, JavaScript, and Native platforms.
-
v2.2.20-Beta2 Pre-release View Details →
Kotlin v2.2.20-Beta2 delivers significant K2 compiler stability improvements, expanded contract system capabilities for operators and generics, and enhanced…
-
v2.2.10-RC Pre-release View Details →
Kotlin v2.2.10-RC delivers critical stability fixes for Kotlin/Native on Apple Watch and resolves compiler issues affecting Compose development.
-
v2.2.20-Beta1 Pre-release View Details →
Kotlin 2.2.20-Beta1 delivers significant Analysis API stability improvements addressing red code issues in K2 IDE, enhanced contract support for operators and…
-
v2.2.0 Major Release View Details →
Kotlin 2.2.0 delivers production-ready context parameters, significant K2 compiler optimizations reducing memory usage and improving type inference, and…
-
v2.2.0-RC3 Pre-release View Details →
Kotlin v2.2.0-RC3 addresses three critical stability issues affecting compiler, JavaScript, and Kotlin/Native platforms.
-
v2.2.0-RC2 Pre-release View Details →
Kotlin v2.2.0-RC2 focuses on stability fixes across multiple compilation targets and tooling.
-
v2.2.0-RC Pre-release View Details →
Kotlin v2.2.0-RC delivers critical stability fixes across compiler, Gradle integration, and multiplatform targets.
-
v2.1.21 View Details →
Kotlin v2.1.21 is a patch release focused on stability and compatibility, addressing critical regressions from v2.1.20 in Kotlin/Native, Kotlin/JS, and…
-
v2.1.21-RC2 Pre-release View Details →
Kotlin v2.1.21-RC2 addresses a regression in the Kotlin/JS Gradle plugin where custom environment variables could not be set in KotlinJsTest tasks.
-
v2.2.0-Beta2 Pre-release View Details →
Kotlin 2.2.0-Beta2 delivers significant K2 compiler stability with 50+ Analysis API and FIR fixes, enhances Compose compiler with new default optimizations…
-
v2.1.21-RC Pre-release View Details →
Kotlin v2.1.21-RC is a maintenance release focused on stability, fixing critical regressions in Kotlin/Native, Compose compiler, and Kotlin/JS introduced in…
-
v2.2.0-Beta1 Pre-release View Details →
Kotlin v2.2.0-Beta1 stabilizes context parameters across the compiler and Analysis API while enabling JVM default interface methods by default.
-
v2.1.20 View Details →
Kotlin v2.1.20 delivers substantial improvements to the Analysis API with new symbol capabilities and performance optimizations in FIR compilation.
-
v2.1.20-RC3 Pre-release View Details →
Kotlin v2.1.20-RC3 addresses critical stability issues for iOS development, including K2 compiler fixes for method inheritance with default parameters and…
-
v2.1.20-RC2 Pre-release View Details →
Kotlin v2.1.20-RC2 addresses critical compiler bugs in K2, Compose, and Native toolchains while improving Gradle plugin stability.
-
v2.1.20-RC Pre-release View Details →
Kotlin v2.1.20-RC delivers critical stability fixes across the K2 compiler, Compose plugin, and Gradle tooling.
-
v2.1.20-Beta2 Pre-release View Details →
Kotlin 2.1.20-Beta2 delivers substantial performance improvements across the FIR analysis pipeline, enhanced support for context receivers in multiplatform…
-
v2.1.10 View Details →
Kotlin v2.1.10 focuses on stability and reliability across multiplatform development.
-
v2.1.10-RC2 Pre-release View Details →
Kotlin v2.1.10-RC2 addresses critical stability issues in Compose and compiler visibility handling.
-
v2.1.10-RC Pre-release View Details →
Kotlin 2.1.10-RC focuses on stability and compatibility fixes across the K2 compiler, Compose, and multiplatform tooling.
-
v2.1.20-Beta1 Pre-release View Details →
Kotlin v2.1.20-Beta1 delivers significant Analysis API enhancements with new symbol capabilities and performance optimizations, while advancing K2 compiler…
-
v2.1.0 Major Release View Details →
Kotlin 2.1.0 delivers significant Analysis API stability improvements with Wasm support, enhanced K2 compiler reliability through 50+ bug fixes, and better IDE…
-
v2.1.0-RC2 Pre-release View Details →
Kotlin v2.1.0-RC2 focuses on stability fixes across the K2 compiler, Compose multiplatform support, and JavaScript interop.
-
v2.1.0-RC Pre-release View Details →
Kotlin v2.1.0-RC delivers critical stability fixes across the K2 compiler, Compose integration, and Gradle tooling.
-
v2.1.0-Beta2 Pre-release View Details →
Kotlin 2.1.0-Beta2 delivers significant performance improvements across the Analysis API with caching and lazy resolution, adds Xcode 16 support for Apple…
-
v2.0.21 View Details →
Kotlin v2.0.21 delivers critical stability improvements focused on Xcode 16 compatibility and K2 compiler robustness.
-
v2.0.21-RC Pre-release View Details →
Kotlin 2.0.21-RC focuses on Apple ecosystem compatibility with full Xcode 16 support and platform library updates.
-
v2.1.0-Beta1 Pre-release View Details →
Kotlin v2.1.0-Beta1 strengthens the K2 compiler with 100+ fixes addressing type system edge cases, exhaustiveness checking, and diagnostics accuracy.
-
v2.0.20 View Details →
Kotlin v2.0.20 delivers major Analysis API stabilization with Kt-to-Ka prefix migration, significant K2 compiler performance optimizations, and fixes for over…
-
v2.0.20-RC2 Pre-release View Details →
Kotlin v2.0.20-RC2 addresses critical stability issues across K2 compiler, native platforms, and JavaScript targets.
-
v2.0.20-RC Pre-release View Details →
Kotlin 2.0.20-RC focuses on stabilizing the K2 compiler with critical fixes for type inference, generics resolution, and captured receiver handling.
-
v2.0.10 View Details →
Kotlin 2.0.10 is a stability-focused patch release addressing 40+ K2 compiler regressions across type inference, generics, coroutines, and Java interop.
-
v2.0.10-RC2 Pre-release View Details →
Kotlin 2.0.10-RC2 addresses a critical K2 compiler issue affecting kotlinx serialization users.
-
v1.9.25 View Details →
Kotlin v1.9.25 is a technical maintenance release focused on IntelliJ IDEA integration.
-
v2.0.10-RC Pre-release View Details →
Kotlin v2.0.10-RC delivers critical stability improvements for the K2 compiler with 40+ bug fixes addressing type inference, generics, and multiplatform…
-
v2.0.20-Beta2 Pre-release View Details →
Kotlin v2.0.20-Beta2 delivers significant K2 compiler stability improvements with 100+ bug fixes across type inference, sealed classes, and enum handling.
-
v2.0.20-Beta1 Pre-release View Details →
Kotlin 2.0.20-Beta1 delivers significant Analysis API improvements with symbol naming consistency and origin tracking enhancements.
-
v2.0.0 Major Release View Details →
Kotlin 2.0.0 Analysis API delivers significant performance improvements through multi-threaded resolve and memory optimization fixes, while expanding library…
-
v2.0.0-RC3 Pre-release View Details →
Kotlin v2.0.0-RC3 delivers critical K2 compiler stability improvements focusing on type inference edge cases and multiplatform tooling.
-
v1.9.24 View Details →
Kotlin v1.9.24 delivers critical bug fixes across Wasm, Native, and Gradle tooling.
-
v2.0.0-RC2 Pre-release View Details →
Kotlin v2.0.0-RC2 focuses on K2 compiler maturity with extensive bug fixes for type inference, smart casting, and cross-platform compatibility.
-
v2.0.0-RC1 Pre-release View Details →
Kotlin 2.0.0-RC1 stabilizes the K2 compiler by removing pre-release status and delivering over 200 bug fixes across Analysis API, type inference, Java…
-
v2.0.0-Beta5 Pre-release View Details →
Kotlin 2.0.0-Beta5 significantly improves Wasm interoperability with TypeScript support and partial linkage, optimizes JVM lambda generation via invokedynamic…
-
v1.9.23 View Details →
Kotlin 1.9.23 delivers critical fixes for Apple ecosystem compatibility with Xcode 15.3 and improves build tooling with JSON reports and enhanced metrics.
-
v2.0.0-Beta4 Pre-release View Details →
Kotlin v2.0.0-Beta4 delivers critical performance improvements, particularly a 50GB memory allocation fix, alongside extensive compiler stability enhancements…
-
v2.0.0-Beta3 Pre-release View Details →
Kotlin v2.0.0-Beta3 delivers significant K2 compiler improvements with over 100 bug fixes focused on analysis accuracy, Java interoperability, and IDE…
-
v1.9.22 View Details →
Kotlin v1.9.22 is a maintenance release focused on stability across Kotlin/Native, Gradle tooling, and JavaScript compilation.
-
v2.0.0-Beta2 Pre-release View Details →
Kotlin 2.0.0-Beta2 delivers substantial K2 compiler stability improvements with 100+ bug fixes across type inference, smartcasts, and diagnostics.
-
v1.9.21 View Details →
Kotlin v1.9.21 delivers critical bug fixes and stability improvements across multiplatform, JavaScript, and Gradle tooling.
-
v2.0.0-Beta1 Pre-release View Details →
Kotlin 2.0.0-Beta1 delivers substantial K2 compiler maturity with 40+ Analysis API performance optimizations and 100+ critical bug fixes addressing IDE…
-
v1.9.20 View Details →
Kotlin 1.9.20 delivers substantial improvements to the K2 compiler's Analysis API with new source shadowing capabilities and numerous performance optimizations…
-
v1.9.20-RC2 Pre-release View Details →
Kotlin v1.9.20-RC2 addresses critical compiler stability issues, particularly a Kotlin/Native crash with ::class expressions and JavaScript compilation.
-
v1.9.20-RC Pre-release View Details →
Kotlin v1.9.20-RC delivers critical stability improvements for mobile developers, including fixes for Kotlin/Native memory issues, Xcode 15 compatibility, and…
-
v1.9.20-Beta2 Pre-release View Details →
Kotlin 1.9.20-Beta2 focuses on stabilizing multiplatform and WebAssembly support with critical bug fixes.
-
v1.9.20-Beta Pre-release View Details →
Kotlin 1.9.20-Beta focuses on stabilizing the K2 compiler with over 100 bug fixes, particularly for Kotlin Multiplatform and Analysis API.
-
v1.9.10 View Details →
Kotlin 1.9.10 is a patch release focused on stability and compatibility, addressing critical regressions from 1.9.0 and adding support for JDK 21 and Xcode 15.